A conventional thin plate-conveying container for accommodating and conveying a semiconductor wafer includes a container body, a lid for closing an opening formed in the container body, and a lock mechanism for engaging the lid with the container body, with the opening of the container body being closed, in order to prevent dust from adhering to the semiconductor wafer. (For reference, see Japanese Patent Application Laid-Open Publication No. Hei 11-159218.)
The lock mechanism is composed of a latch mechanism including a latch plate that disengageably engages with the container body, and a rotatable rotation plate linked to the latch plate through a link arm member.
The rotation plate exerts a rotating force on the latch plate as an engaging force for engagement with the container body and as a disengaging force for disengagement from the container body. By rotational operation of the rotation plate, the engagement of the latch plate with the container body and the disengagement of the latch plate from the container body can be performed, and thereby the opening and closing of the opening of the container body can be carried out.
Incidentally, a structure using a cam mechanism between the rotation plate and an engagement pawl is also known. (For reference, see Japanese Patent Application Laid-Open Publication No. 2005-306411.)
However, the conventional opening/closing structure for the thin plate-conveying container is not provided with a device for holding the rotation plate at an engagement rotation position at which a lock member such as the latch plate is engaged with the container body and at a disengagement rotation position at which the lock member is disengaged from the container body.
Thus, when, during conveyance, vibrations for example are applied to the thin plate-conveying container having a semiconductor wafer accommodated therein, a problem arises where the rotation plate rotates and thus the lock member is disengaged from the container body.
Moreover, when the rotation plate is rotated for the disengagement of the lock member from the container body, it is difficult to determine whether or not the disengagement of the lock member from the container body is completed. This renders impossible the complete disengagement of the lock member from the container body. When the lid is removed from the container body with the lock member incompletely disengaged from the container body, a problem arises where damage to the lock member, the container body, and the lid is caused by the lock member being caught in the container body.